1. Field of the Invention
The present invention is directed to a composition for keratinous fibers and to methods of treating keratinous fibers with the composition in order to provide protection from extrinsic damage and to provide improved styling properties and other qualities. For example, the inventive composition can provide protection to hair while improving combability and curl formation. More particularly, the present invention is directed to a composition comprising plant extracts that provides protection benefits to keratinous fibers, including hair, eyelashes, and eyebrows.
Keratinous fibers, especially hair, are constantly exposed to harsh extrinsic conditions such as sun, chemical damage, e.g., from detergents, bleaching, relaxing, dyeing, and permanent waving, and heat, e.g., from hair dryers or curlers. These external factors generally result in damage to the keratinous fibers. There is a need, therefore, for cosmetic products that are useful in restoring and protecting keratinous fibers from such harsh extrinsic conditions.
2. Description of the Prior Art
In this age of the immense popularity of “natural” based consumer products, specific groups of plant extracts have been identified for their “healing” or protecting properties with regard to keratinous tissue. In particular, plant extracts have been used in numerous skin care compositions such as: compositions containing carrot, tomato, tobacco, bean or potato extracts for the repair of sun damaged skin (U.S. Pat. No. 5,547,997); compositions containing actzuki bean, catechu, or avocado extracts for preventing and improving multiple skin conditions (European Patent EP965328 A1); compositions containing herbal extracts such as dill, horseradish, oats, neem, beet, broccoli, tea, pumpkin, soybean, barley, walnut, flax, ginseng, poppy, avocado, pea or sesame for the delivery of active ingredients in the form of adhesive strips which remove keratotic plugs from skin pores (U.S. Pat. No. 5,985,300); topical formulations containing orange, avocado, watermelon, banana, lemon, palm oil, or coconut oil for the treatment of redness, swelling, itching, and soreness of the skin (U.S. Pat. No. 5,932,230); skin cream compositions containing the juice of an avocado, cucumber, lemon, or weeping willow for cleansing, moisturizing, nourishing and healing the skin (U.S. Pat. No. 4,722,843); a skin moisturizing and cleansing cream comprising a mixture of a predominant amount of fresh fruit (U.S. Pat. No. 4,297,374); and skin moisturizing and sunscreen compositions containing biological extracts such as green tea extract, horsetail extract, sunflower extract, and wheat germ extract (U.S. Pat. No. 5,788,954).
The healing properties of certain plant extracts have also been used in hair care compositions such as: hair cosmetic compositions containing a plant extract chosen from bark of birch, grass of rosemary, and avocado (U.S. Pat. No. 4,839,168); compositions for treating dandruff (U.S. Pat. No. 5,053,222) and hair growth-promoting compositions (JP62099319) containing mistletoe; and compositions containing a bean extract (JP59101414) that correct damaged hair.
While popular opinion regarding some of the touted uses of plant extracts ranges from skepticism to disbelief, there appears to be a firm scientific basis for many of the assertions. For example, many plant extracts contain lectins, also referred to as agglutinins, affinitins, phytoagglutinins, phasins or protecting. These are a group of proteins or glycoproteins, of both plant and animal origin, that have specific binding affinity to sugar groups which exist in polysaccharides or glycoproteins. Not to be limited as to theory, it is believed that this binding affinity to sugars is responsible for the observed therapeutic or protective properties that make plant extracts a choice material for use in target delivery of active ingredients or therapeutic agents.
U.S. Pat. No. 4,217,341, for example, discloses compositions containing lectins which bind and agglutinate dental-plaque producing bacteria, thereby inhibiting the adherence of said bacteria to smooth surfaces such as teeth surfaces. Similarly, U.S. Pat. No. 5,607,679 discloses a method of treatment of a skin disease by binding lectins to a sialylated TF antigen of the skin. The specific affinity of lectins for sugars is also taught in U.S. Pat. No. 5,510,120 and EP0481701 B1 where the lectin is covalently bound to a liposome which also contains an active ingredient. Thus the active is delivered to the specific site desired.
Plant extracts and lectins are also used in the characterization of carbohydrates because of their ability to bind to some sugar molecules and moieties, and their ability to cause cell agglutination by binding to the glycoproteins located in the cell membrane. The nature of the binding sites can be determined by the hapten-inhibition test. See Kornfeld, S. and Kornfeld, R., Lectins in the Study of Glycoproteins (1978). In this assay, various carbohydrates are tested for their ability to inhibit the lectin-induced agglutination of the test cells. It has been shown that various lectins react with a number of different carbohydrates, both simple and complex sugars. See Kornfeld, S. and Kornfeld, R., Glycoproteins of Blood Cells and Plasma (1971). In the majority of cases, the affinity of lectins to complex oligosaccharides is much greater than that to simple sugars. Among the lectins shown to have carbohydrate-binding sites of the complex type are the lectins from potato (Solanum tuberosum). Allen, A. K. and Neuberger, A., J. Biochem. 135, 307-314 (1973). Solanum tuberosum agglutinin (STA), which has an affinity for N-acetyl-β-D-glucosamine oligomers, is a glycoprotein containing approximately equivalent amounts of protein and carbohydrate.